<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
</head>

<body>
<script  language="javascript"> 
    // function A(callback) {
    //     callback();
    //     console.log('I am main')
    // }
    // function B() {
    //     setTimeout('console.log("I am ee")', 3000)
    // }
    // function say(value) {
    //     alert(value)
    // }
    // alert(say)
    // alert(say('hi js.'))
    // window.onload =  A(B);
    // function say(value) {
    //     alert(value);
    // }
    // function execute (someFunction, value) {
    //     someFunction(value);
    // }
    // execute(say,'hi js.')
    function execute (someFunction ,value) {
        someFunction(value);
    }
    execute(function(value) {alert(value);}, 'hi js.')
</script>
</body>
</html>